The team, led by Nicholas X. Fang, a professor of mechanical science and engineering at Illinois, successfully focused ultrasound waves through a flat metamaterial lens on a spot roughly half the width of a wavelength at 60.5 kHz using a network of fluid-filled Helmholtz resonators.
According to the results, published in the May 15 issue of the journal Physical Review Letters, the acoustic system is analogous to an inductor-capacitor circuit. The transmission channels act as a series of inductors, and the Helmholtz resonators, which Fang describes as cavities that house resonating waves and oscillate at certain sonic frequencies almost as a musical instrument would, act as capacitors.
Fang said acoustic imaging is somewhat analogous to optical imaging in that bending sound is similar to bending light. But compared with optical and X-ray imaging, creating an image from sound is “a lot safer, which is why we use sonography on pregnant women,” said Shu Zhang, a U. of I. graduate student who along with Leilei Yin, a microscopist at the Beckman Institute, are co-authors of the paper.
Although safer, the resultant image resolution of acoustic imaging is still not as sharp or accurate as conventional optical imaging.
“With acoustic imaging, you can’t see anything that’s smaller than a few millimeters,” said Fang, who also is a researcher at the institute. “The image resolution is getting better and better, but it’s still not as convenient or accurate as optical imaging.”
The best tool for tumor detection is still the optical imaging, but exposure to certain types of electromagnetic radiation such as X-rays also has its health risks, Fang noted.
“If we wish to detect or screen early stage tumors in the human body using acoustic imaging, then better resolution and higher contrast are equally important,” he said. “In the body, tumors are often surrounded by hard tissues with high contrast, so you can’t see them clearly, and acoustic imaging may provide more details than optical imaging methods.”
Fang said that the application of acoustic imaging technology goes beyond medicine. Eventually, the technology could lead to “a completely new suite of data that previously wasn’t available to us using just natural materials,” he said.
In the field of non-destructive testing, the structural soundness of a building or a bridge could be checked for hairline cracks with acoustic imaging, as could other deeply embedded flaws invisible to the eye or unable to be detected by optical imaging.
“Acoustic imaging is a different means of detecting and probing things, beyond optical imaging,” Fang said.
Fang said acoustic imaging could also lead to better underwater stealth technology, possibly even an “acoustic cloak” that would act as camouflage for submarines. “Right now, the goal is to bring this ‘lab science’ out of the lab and create a practical device or system that will allow us to use acoustic imaging in a variety of situations,” Fang said.
Funding for this research was provided by the Defense Advanced Research Projects Agency, the central research and development agency for the U.S. Department of Defense.
Phil Ciciora | University of Illinois
Further reports about: > Defense > Helmholtz > Illinois River Watershed > Superlens > Ultrasound waves > X-rays > acoustic system > electromagnetic radiation > hairline cracks > high-resolution ultrasound imaging > inductor-capacitor circuit > metamaterial lens > non-destructive structural testing of buildings and bridges > novel underwater stealth technology > sonic frequencies
Nano-scale process may speed arrival of cheaper hi-tech products
09.11.2018 | University of Edinburgh
Nuclear fusion: wrestling with burning questions on the control of 'burning plasmas'
25.10.2018 | Lehigh University
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences